Sökning: "Marine ecology"
Visar resultat 21 - 25 av 342 avhandlingar innehållade orden Marine ecology.
21. Non-indigenous zooplankton : the role of predatory cladocerans and of copepods in trophic dynamics
Sammanfattning : Human-mediated introductions of non-indigenous species now threaten to homogenize the biota of the Globe, causing huge economic and ecological damage. This thesis studies the ecological role of 3 invasive planktonic crustaceans, the omnivorous copepod Acartia tonsa (western Atlantic and Indo-Pacific) and the predatory cladocerans, Cercopagis pengoi (Ponto-Caspian) and Bythotrephes longimanus (Eurasian). LÄS MER
22. Direct and indirect effects of fish predation and excretion in aquatic food webs
Sammanfattning : The aim of this thesis was to elucidate the mechanisms by which planktivorous fish can affect planktonic communities in lakes and how they may affect benthic communities through their effects on planktonic communities. In a laboratory experiment, nutrients released by fish increased algal biomass and altered phytoplankton community structure, suggesting that fish can affect phytoplankton by directly releasing nutrients. LÄS MER
23. Limitations and possibilities for microbial degradation of organic contaminants in aquifers
Sammanfattning : Many factors can influence the rate of microbial degradation of organic contaminants in aquifers. Some of these factors, e.g. LÄS MER
24. Effects of habitat structure on tropical fish assemblages
Sammanfattning : Rates of habitat alteration and degradation are increasing worldwide due to anthropogenic influence. On coral reefs, the loss of live coral reduces structural complexity while facilitating algal increase. In many coastal lagoons seagrass and corals are cleared to make room for cultivated macroalgae. LÄS MER
25. Distribution patterns of macroinvertebrates in vegetated shallow soft-bottom bays of the Baltic Sea
Sammanfattning : .... LÄS MER